Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
  • C08B1/00—Preparatory treatment of cellulose for making derivatives thereof, e.g. pre-treatment, pre-soaking, activation
  • C08B1/003—Preparation of cellulose solutions, i.e. dopes, with different possible solvents, e.g. ionic liquids
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L1/00—Compositions of cellulose, modified cellulose or cellulose derivatives
  • C08L1/02—Cellulose; Modified cellulose
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F2/00—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof

Definitions

• the present invention relates to a method for producing a cellulosic molding, in particular cellulosic fibers.
• N-methylmorpholine-N-oxide is preferably used as the solvent.
• NMMO is used for the term “tertiary amine oxides”, NMMO additionally representing the N-methylmorpholine-N-oxide which is preferably used today.
• Tertiary amine oxides have long been known as alternative solvents for cellulose. From US Pat. No. 2,179,181 it is known, for example, that tertiary amine oxides can dissolve high-quality chemical pulp without derivatization and that cellulosic shaped bodies such as fibers can be obtained from these solutions by precipitation. In US Pat. Nos. 3,447,939, 3,447,956 and 3,508,941 describe further processes for the preparation of cellulosic solutions, cyclic amine oxides preferably being used as solvents. In all of these processes, cellulose is physically dissolved at an elevated temperature.
• the cellulose is preactivated before the solution preparation, which is also carried out in an extruder.
• the DD-A mentioned is based on an NMMO-containing cellulose suspension which is first homogenized in a stirred vessel. The material density is then raised to 12.5% by mass by centrifugation or pressing, to a water content of 10 - converted (based on NMMO) 15% by mass of dried and in an extruder with a degassing zone at temperatures of 75-120 * C into a clear solution .
• EP-A-0 356 419 by the applicant describes a process which is preferably carried out in a thin-film treatment apparatus in which a suspension of the comminuted pulp in an aqueous tertiary amine oxide is transported in the form of a thin layer and transported over a heating surface in the form of a thin layer. the surface of this thin layer being subjected to a vacuum. When the suspension is transported over the heating surface, water is evaporated off and the cellulose can be brought into solution, so that a spinnable cellulose solution is discharged from the film spinner. All of the processes described above use high-quality chemical pulp as a starting material, which is obtained, for example, from beech wood or spruce wood. Little is known in the prior art about the use of other cellulose-containing materials.
• NMMO Processing lignocellulosic materials in the NMMO process is known from WO 86/05526. Relatively aggressive conditions are recommended for processing. For example, poplar wood is first subjected to a special hydrolysis process and the solid product obtained is mixed at room temperature with NMMO, which has a water content of 13.5%.
• the NMMO used is the monohydrate of the NMMO present at room temperature in the solid state (melting point> 70 * C). The solid mixture is homogenized and heated to 130 ° C and melted, the hydrolyzed wood dissolving.
• lignocellulosic material can be dissolved in a solution of NMMO in dimethyl sulfoxide.
• the NMMO used is not an aqueous solution but has a water content of 15%, which also corresponds approximately to the monohydrate.
• the object of the invention is therefore to improve the process for the production of cellulosic moldings, in particular fibers, by the amine oxide process in such a way that pulp materials which are only sparingly soluble in aqueous amine oxide can be used as starting material, or that pulp materials are used can, which are soluble in aqueous amine oxide, but whose solutions are either not or only spinnable in the prior art.
• Cellulose is formed, and the solution is shaped using a molding tool, in particular a spinneret, and introduced into a coagulation bath in order to precipitate the dissolved cellulose, characterized in that a suspension which contains a cellulose-containing material is used to form the cellulose solution that one
• pulp sources such as cotton edge sections from clothing sources and other cellulosic waste
• pulps that are dissolved, but whose solution can only be spun at uneconomical concentration ratios or only with difficulty such as the pulp of the Alistaple LD type 9.2
• the duration and intensity of the applied pulp can be dissolved without chemical activation treatment in the amine oxide process and processed into fibers if they are previously exposed to electron radiation.
• Electron radiation that is to say the irradiated dose, naturally depends on the type of raw material used, but can easily be found out by the person skilled in the art by preliminary experiments.
• cellulose carbamate The use of electron beams to modify the degree of polymerization of cellulose carbamate is known.
• a cellulose derivative i.e. the cellulose carbamate, irradiated.
• an aqueous solution of the tertiary amine oxide which contains between 60 and 80% by mass of amine oxide is used to prepare the suspension.
• a further preferred embodiment of the method according to the invention is characterized in that additionally unirradiated cellulosic material is used as the cellulosic material.
• mixtures of an irradiated and an unirradiated cellulosic material can also be used excellently in the process.
• the irradiated cellulosic material can be added on the one hand to further improve the processability, a pulp that is already suitable in the unirradiated state for dissolving and spinning, mostly rather low molecular weight.
• the irradiation can give the irradiated pulp such excellent properties that it can be mixed with less suitable materials for the amine oxide process, for example high-molecular pulp or the textiles mentioned, without having to accept significant losses in processing .
• a further preferred embodiment of the method according to the invention is therefore characterized in that the solution is formed by continuously introducing the suspension into an evacuable, heatable vessel, mechanically spreading the introduced suspension to form two surfaces, the spread, in a film-like manner Suspension for the supply of heat is brought into contact with a heating surface via a surface, the spread suspension is transported over the heating surface with intensive mixing, while the second surface facing away from this heating surface is subjected to a reduced pressure during transport over the heating surface in order to evaporate water, until the cellulose-containing material has dissolved and the solution is continuously withdrawn from the vessel.
• a useful device in which this embodiment of the method according to the invention can be carried out is a thin-film treatment apparatus, such as is used e.g. the company Buss (Switzerland) produces as a film truder. It has been shown that such a thin-film treatment apparatus is particularly well suited to dissolving these pulps and these cellulose-containing materials. This is believed to be due to the high shear forces that occur in the thin film processor.
• a thin-film treatment apparatus such as is used e.g. the company Buss (Switzerland) produces as a film truder. It has been shown that such a thin-film treatment apparatus is particularly well suited to dissolving these pulps and these cellulose-containing materials. This is believed to be due to the high shear forces that occur in the thin film processor.
• the molecular weight profile (dN / N [%] against log MG pseudopolystyrene) of the Viscokraft LV pulp (manufacturer: International Paper), a pulp that can be used well in the amine oxide process due to its solubility behavior, was recorded by means of gel permeation chromatography (GPC).
• the size dN / N (%) describes the percentage of the molar mass fraction.
• the pulp was dissolved in LiCl / DMAc and chromatographed on the HPLC column with defined exclusion volumes. It was detected via a refractive index detector.
• FIG. La in all figures: abscissa: log MG pseudopolystyrene; ordinate: dN / N [%]) and shows a relatively narrow distribution with a maximum of the logarithm of the molecular weight (log MG pseudopolystyrene) of about 5, 75.
• shredded pulp Viscokraft LV (average degree of polymerization: 450) was first suspended in aqueous, 50% NMMO, placed in a kneader (type: IKA laboratory kneader HKD-T; manufacturer: IKA laboratory technology) and one hour left impregnated. Of the kneader was evaporated with a performed at 130 * C temperature-controlled heating medium and by time in defined steps reduction of the negative pressure water then by heating, was completely gone into solution to the pulp.
• Grade 4 many undissolved particles and long crystallites can be seen; Grade 3: somewhat shorter crystallites can be seen; Grade 2: few crystallites can be seen; Note 1: practically no undissolved particles can be seen.
• Viscokraft LV begins to dissolve after about 10 minutes, the dissolution process subsequently being fairly even and completing after about 23 minutes.
• the temperature at this time is 99.0'C.
• a melt index device from Davenport used in plastics processing was used as the spinning apparatus.
• This device consists of a heated, temperature-controlled cylinder into which the spinning mass is filled.
• the spinning mass is extruded through the spinneret attached to the underside of the cylinder by means of a piston which is loaded with a weight.
• the spinning mass introduced into the spinning apparatus was extruded at various temperatures (between 90 * C and 120 * C) through a nozzle with a diameter of 100 ⁇ m, passed through an air gap (3 cm) with dry air into an aqueous precipitation bath, deflected and drawn off via a godet, which was provided behind the precipitation bath.
• the spinning mass output through the nozzle was 0.030 g / min.
• the spinning behavior was examined by determining the maximum take-off speed (m / min). This maximum take-off speed is the speed at a predetermined temperature at which the drawn-off filament breaks. It is therefore a measure of the spinning behavior. The higher this value, the better the spinning behavior.
• Table 2a shows that the spinnability of the pulp can be improved with radiation.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Polymers & Plastics (AREA)
• Health & Medical Sciences (AREA)
• General Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Biochemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Textile Engineering (AREA)
• Paper (AREA)
• Polysaccharides And Polysaccharide Derivatives (AREA)
• Manufacture Of Macromolecular Shaped Articles (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
• Artificial Filaments (AREA)
• Moulding By Coating Moulds (AREA)
• Processes Of Treating Macromolecular Substances (AREA)
• Materials For Medical Uses (AREA)

Applications Claiming Priority (3)

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• 1995
  • 1995-09-19 AT AT0155795A patent/AT402739B/de not_active IP Right Cessation
• 1996
  • 1996-09-13 TW TW085111212A patent/TW324038B/zh not_active IP Right Cessation
  • 1996-09-13 ZA ZA967753A patent/ZA967753B/xx unknown
  • 1996-09-19 CA CA002205089A patent/CA2205089A1/fr not_active Abandoned
  • 1996-09-19 EP EP96929963A patent/EP0792393B1/fr not_active Expired - Lifetime
  • 1996-09-19 WO PCT/AT1996/000167 patent/WO1997011213A1/fr active IP Right Grant
  • 1996-09-19 AU AU69184/96A patent/AU707154B2/en not_active Ceased
  • 1996-09-19 JP JP9512238A patent/JPH10509222A/ja not_active Ceased
  • 1996-09-19 CN CN96191487A patent/CN1080327C/zh not_active Expired - Fee Related
  • 1996-09-19 US US08/836,660 patent/US5788939A/en not_active Expired - Fee Related
  • 1996-09-19 BR BR9606649A patent/BR9606649A/pt not_active IP Right Cessation
  • 1996-09-19 DE DE59600089T patent/DE59600089D1/de not_active Expired - Fee Related
  • 1996-09-19 AT AT96929963T patent/ATE162859T1/de not_active IP Right Cessation
  • 1996-09-19 DK DK96929963T patent/DK0792393T3/da active
  • 1996-09-19 KR KR1019970703343A patent/KR100430920B1/ko not_active IP Right Cessation
  • 1996-09-19 ES ES96929963T patent/ES2114757T3/es not_active Expired - Lifetime
• 1997
  • 1997-05-16 NO NO19972271A patent/NO310116B1/no not_active IP Right Cessation
• 1998
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